Apparatus for controlling the movement of vehicles on railroads



July 22,-1930. F, .1. SPRAGUE 1,771,149 APPARATUS FOR coumommc m:uovsum- 9F vsarcnss' on numolms ori inal Filed ApriI-IZ. 192'! A TTONEYSJ Patented July 2 2, 1930 V rorrrcs FRANK J. sPRAGUE, OF NEW YORK,N. Y.

APPARATUSFOR CONTROLLING THE MOVEMENT or vEHroLnsoN RAILROADS" Originalapplication filed. April 12, 1927, Serial, No.

' 1 1929. Serial This application isfiled as a division of my priorapplication, Ser. No. 183,193 of April 12,1927, for apparatusfor-controlling movement of vehicles on railroads, and the subjecthereof forms part ofthe apparatus disclosed in the aforesaidapplication.

. a My inventionv relates to an improvement in automatictraincontrolsystems, and particularly to the features. known as'forestallingg and resetting, the former being .an operation by which the engineermay, by the performance of a suitable manual act, prevent the coming onof an automatic brake application, and the latter an operation by Whichthe brake controlling apparatus may be restored to normal condition,afterwhich the 1 brakes. (if applied) may be released and freerunningconditions established.

In much of present practice the forestallingand resetting operations areeffected by mechanisms differently placed, the forestalling being donein, the cab, and the resetting through a switch or other device situatedat such inconvenient point as will require the train to be stoppedbefore it can: be used, so as to prevent release of the brakes,appl1edinresponse to a track, initiated impulse, be fore: the train has come torest, although sometimes this reset switch is made inconvenient butpossibly accessible when moving at slow speeds. I

To place some restriction upon the act of forestalling, which unlesslimited by the condition that a train must be actually braked or has hadits speed reduced to some predetermined ratealthough present practice 1and rules actually permit forestalling at any speed and without anypre-application of the brakesit has been proposed to limit the timeperiod in which the engineer may forestall an automatic brakeapplicationwhen receiving a track impulse. This is done in. certain electricallycontrolled systems by com necting a forestalling switch and circuits sothat atterimanual operation of the switch by the engineer theforestalling circuit will be closed, and the essential circuit will bemaintained for only a limited time, the movement of the switch handleinitiating a motive force which after a short interval W-lll open the 7second, if he forestalls toozsoon; and, finally,

183,193. Dividedamr this application filed m 6, No. 376,399. Q 1

essential circuit, just as the pilotvci-rcuits are made and opened in myLettersPatent No. 660,065 on the multiple-unit system of train acontrol.

With this arrangement, thehengineen, on

approachinga stop indication point within a distance less than he willcovenin. termined time, a hundred to a thousandfeet or more, accorda=predeing to the speed of a'train, moves hisswitch totheforestallingposition,,closes the forestallmg c 1rcu1t andinitiatesthe motive force,WlllCh Wlll open the essential circuit auto-.

matically in a predetermined time-say 15' seconds. After passing-thestop indication point, if he returns theswitch to the normal positionwithin the time period there; will be no automatic braking, althoughsomeipart of the equipment may be responsive. But if the switch is heldin the forestalling positionffor longer than the time period the. brakeswill 7 come on. 7

Thus there are three conditions in which the automatic brake applicationmay take j; place as a result of passing a stop indication point.First,. if the engineer does nothing;

he holdson too long. Anyofthese conditlons may possibly act adversely asregards train movements.

With the automatic brakeapplicationin effect, the amount of brakinghismade such as to bring the train to a stop, after. which the engineer, orfireman must get. down 'from. the cab, or climb out toa positiondiflicult. of access when the locomotive ismoving, to reset the brakeinitiating apparatus, so that the engineer may release the brakesmanually.

I The main object of thus separating the forestalling and resettingactions, and providing for a time limit. is to induce some measure ofalertness on the part of the engineer, under. possible penalty, and; toinsure that once the brakes have actually come on automatically thetrain shall be stopped before the engineer can. release them.

which may be anything, from r There are serious objections to bothpracoperations,

enable the brakes to be released. This latter act cannot be performed attimes without serious danger, as in tunnels, snow-sheds and on trestles,or in proximity to passing trains and under conditions of poorvisibility.

I desire, therefore, to provide definite limitations upon the act offorestalling, as well as upon the act of resetting, while the timingmechanism for opening the forestalling circuit may be omitted entirely.I plan, also, to combine in a single mechanism-operated in the cab-boththe forestalling and resetting and for compelling, under possiblepenalty, acknowledgment of the receipt of a brake initiating impulsefrom the track. This mechanism may conveniently be referred to as anacknowledging device.

My invention will conduce to safety and convenience, and eliminatedelays, while making it possible to impose upon the engineer suchprecautionary conditions as are essential to safe operation and themaintenance of the fundamentals of automatic train control systems.

The accompanying drawings and specification illustrate my invention asapplied to a system of automatic train control which cooperates with theusual type of air brake equipment in whole or in part. It is of courseapplicable not only to vehicles propelled by steam but to vehiclesotherwise propelled. It should be noted that the mechanic, electric andpneumatic devices shown in these drawings serve merely to illi'istratethe nature of the invention, and thus do not limit it to theconstruction shown.

In the accompanying drawing which forms part of this application- Figure1 is a diagrammatic illustration of the electric circuits of thevehicle-carried equipment of a train control system which incorporatesmy invention, also indicating in aschematic Way the cooperating trackelements.

Relay R represents the governing element of the circuits. This relay isnormally energized, its maintaining circuit being the following: plus ofbattery H, armature A, contacts 7 6, armature 2, and coil of relay andback to the negative of the battery. As the maintaining circuit of relayR includes its own armature 2 it is a stick relay which, when oncede-energized, cannot be re-energized by way of its normal maintainingcircuit.

The armature A represents an element for changing the electricalcondition of the governing element of the circuits, which element isherein illustrated as a stick relay. The armature A is for convenienceillustrated as biased by a spring 18 and is intended to be controlled bytrack elements. In the specific illustration it is normally held by itsspring against its cooperating contact so as to close the maintainingcircuit of relay R. However, if an active application track element ispassed this armature A is so afiected as to open the maintaining circuitof relay R at contact 7. The word active in this connection refers tothe condition of the track element which is intended to initiateautomatic braking and does not refer to the inherent condition of thetrack element itself. The term track element is likewise employedinits'bloadest sense irrespective of the type of system, whethercontinuous or intermittent, to which my invention is applied. V

For illustrative purposes I have indicated in a schematic way anintermittent inductive type of system, such being fully described in myBritish Patent No. 149,922, or my United States Patent No. 1,669,165 ofMay 8, 1928.

The track element is represented by an application magnet of thecompound type vhich consists of a permanent magnet m provided with softiron poles m m surrounded by neutralizing coils H. The neutralizingcoils a are energized from a battery 150 for clear traffic conditions inwhich case their field neutralizes or deflects he field of the permanentmagnet. For restricted trafiic conditions, however, the neutralizingcoils are de-energized in which case the flux of the permanent magnet iseffective and the track element active. The trafiic control is shown ina conventional way. The receiver of the locomotive is represented byplates p which collect the flux when passing over an active magnet,whereby the armature A. magnetically attracted by the plates 1? andbreaks the circuit of which it forms part.

The stick relay R normally maintains an armature 1 against a contact 1in the normally closed circuit of an electro-pneumatic vent valve V.

The vent valve represents the connecting member between the electric andpneumatic parts of the vehicle-carried equipment, deenergization ofwhich member initiates an automatic brake application. Various pneumaticequipment may be used in connection with my inventionfor instance, theone described in my previously referred to application, Ser. No. 183,193of April 12, 1927.

The circuit for V process through the plus end 'of battery H, and speedcontrolled contacts 130 and 131which are normally electrically connectedby a cylindrical contact 133, to contact 14, contact 123 and contact ofan acknowledging device, F through coil of the vent valve, front contact4i and armature 1 of relay R, back to the negative end of battery H. Thecontact 123 of the acknowledging device F is normally held by a spring12 1 in its upper position so as to bridge contacts 1 1 and 15 and thespeed controlled contacts are also electrically connected throughcontact 138providcd the speed of the train does not exceed apredetermined maximum value. The circuit of-the coil 20 V is thusnormally closed and the vent valve energized. v

- Asmentmned' 'prev1ously, when the stlck "gizing circuits. prisecontacts of a manually operated acknowledging'device, as well asspeedcon- 7 contacts will now be described.

relay P. is die-energized, as happens when passing over an activeapplication track elemcnt,*it cannot here-energized by way of its normalmaintaining circuit, even after such track element is passed andarmatureA has assumed 1ts normal position; such re-energination can onlytake place by way of re-ener- These circuits which comtrolled andinertia controlled The acknowledging device F here illustrated comprisesthe contact 123, which, as

already stated, due to the action of spring 12 1, 'normallybridges thecontacts 14 and 15. Upon manual actuation of the acknowledging device,electric connection between the upper contacts 14 and 15 is broken andconnectionbetween the lower contacts 12 and 13 is established. The speedcontacts are controlled by a cen- 'trifugal speed governor M, which isprovided with a battery brush 130, always connected with the positiveend of the battery H, with a high-speed brush 131, and a low-speed brush132. A rotating contactcylinder 133 electrically connects brushes 130'and 131 unless the train exceeds a high or maximum speed limit, whichmay be of the orderof 50 to 7 M. P. H.; the electrical connection'between the battery brush 130 and the low speed brush 132 is onlymaintained'provided the speed of the train is below a so-called lowspeed limit which may be of the order of to M. P. TL, the values-givenbeing only for the our os'e of illustration.

The pendulum device P comprises a weight iadjustably supported on'apendulum arm 127 which latter is normally retained against" a contact 10by an adjustable spring 126.

The pendulum arm is of conductive material and is connected with thepositive pole of battery H. This pendulum gives a measure of the rateand consequently of the amountof braking required to break the contact10 and to make a contact 9, matters for determination by suitableadjustment to suit the re-' quirements of the road adopting the system.-'The suggestion is made for the purpose ofillustration that contact 10be broken at the commencement of automatic braking and ing.

that contact'9 be made on full service brak- There are threere-energizing circuits for the relay R, all of which go through the backcontacts 12 and 13 of the acknowledging de-- vice F Of these threecircuits the one is the forestalling circuit which goes from plusbattery through pendulum arm 127, pendulum conmatic braking has started.Thus, to forer stall an automatlc brake application the engineer has toclose the acknowledging device before the automatic brake applicationhas taken place.- i

The second re-energizing circuit is the reset circuit which is closed 1fthe braking exceeds a certain rate-thus if ascertain amount of brakinghas taken placeand the pendulum arm 127 contacts with contact 9. By

-manually depressing the acknowledging device the reset circuit is.closed as follows: plus battery, pendulum arm 127, pendulum contact 9,contact 12, contact 123 and contact 13of the acknowledging device, relayR i and back to negative battery.

The third 're-energizing circuit goes through the low-speed contact 132of the speed governor and is closed upon operation of the acknowledgingdevice F provided the speed of the train is below the low-speed limit.This re-energizing circuit can be traced as follows: plus battery,speedcontact 130,

contact segment 133, speed contact 132, contact 12, armature 123 andcontact 13 of the acknowledging device, relay R back to nega-' tivebatter A warning device, audible, visible or both and represented in thedrawing by the audible signal K, is provided; This alarm is energizedwhenever the relay R is de-energized as dropping of armature 1 closesthe circuitof alarm K as-follows: I

-Plus battery, audible signal K, contact 5, armature 1 and back tonegative battery.

" "It should also be noted thata time delay should be provided betweenthe de-energizingof the vent valve and the automatic application of thebrake. This time delay may be varied'from 'the fraction of a second toseveral seconds, depending on the requirements. There are many knownways of introducing such a time delay between the deenergization of thevent valve and the application of the brakes, for instance, the onedescribed inmy above-referred to application #183,193 of April 12, 1927.

Under normal conditions the stick relay is energized'and its armatures 1and 2 are attracted. The acknowledging device F is contacting with itscontact 123 with the con- The speed contact 131- unless'the speedexceeds the maximum speed tacts 14 and 15.

limitis connected with the brush through K contact ring 133 and thus thecoil 20 of the vent valve is energized. If the an A u .train exceeds themaximum speed limit the vent valve is tie-energized with a consequentapplication of the brakes. However, as soon as the train reduces itsspeed below the maximum speed limit the vent valve is automaticallyre-energizedthe relay R not having been de-energizedand the brakes can,neer of the danger conditions ahead, and

that an automatic brake application will be efi'ected unlessforestalling action is taken by him.

Assume now that the engineer is not prepared to heed such warning or isincapacitated, an automatic brake application will then occur.

However, if the engineer is alert and wishes to take advantage of theiorestalling privilege upon the receipt of the warning given by theaudiblesignal K, he will move the acknowledging device F into itsoperating position and immediately release it thereafter. This firstbreaks the circuit of the coil'20 of the vent valve at contacts 14: and15 and bridges the forestalling circuit of the relay R at contacts 12and 13, provided that the forestalling contact 10 is closed by thependulum arm 127 or that the low speed brush 132 is contacting with thecylinder segment 133. The first condition assumes that retardation dueto automatic braking has not yet started and the second conditionassumes that the train is below the low-speed limit. Releasing of theacknowledging device by the engineer returns contact 123 to the uppercontacts 14: and 15, and as in the meantime the relay R has beenre-energized the whole equipment is restored to normal condition.

It has been stated above, that there is a time delay provided betweende-enejrgization of the vent valve and the automatic application of thebrake, also that after a track element is passed, armature A assumes itsnormal closed position. Thus it will appear that when contact 123, afterhaving completed the forestalling circuit, is released and again bridgesthe upper contacts 14: and 15, normal condition of the equipment isrestored without an automatic brake application taking place.

If, on the other hand, the engineer fails to forestall the automaticbrake application,

he may re-energize relay B through the reset circuit by operating theacknowledging device, after sufficient retardation of the train hastaken place to bring the pendulum arm 27 into contact with contact 9.energizing relay I the equipment can be restored to normal by releasingthe acknowledging device.

As illustrated in the drawing, both the torestalling and the resettingcan be efiected irrespective of the position of the pendulum contacts(and thus of the retardation of the train) provided the train is belowthe lowspeed limit. It should be understood, however, that my inventiondoes not necessarily require the use of the low-speed contact. In thesame way the maximum-speed contact may also be omitted.

Various modifications both in regard to the circuits as well as thephysical embodiment of the devices may be employed without deviatingfrom the spirit of the invention, and no undue limitation shouldtherefore be deduced from the specific illustration given, but theappended claims should be construed as broadly as possible in view ofthe prior art.

WV hat I claim as new and desire to secure by Letters Patent is:

1. In an automatic train control system of the permissive type,brake-setting apparatus, a combined forestalling and resetting device,and two pendulum-controlled contactors, said forestalling and resettingdevice permitting, by its identical manual operation, prevention of anautomatic application of the brakes when operated prior to suchapplication provided one of the pendulum-controlled contactors isclosed, and restoration of the apparatus to normal in case an automaticapplication of the brakes has already been started provided that theother pendulum-controlled contactor is closed.

2. In an automatic train control system of the permissive type,brake-setting apparatus, a device to detect deceleration and contactsclosed by said device, an acknowledging mechanism permitting, byidentical manual operation, prevention of an automatic application ofthe brakes when operated prior to such application provided that one ofthe contacts of the device to detect deceleration is closed, andrestoration of the apparatus to normal after an automatic application ofthe brakes provided that another contact of said device is closed.

3. In a system for automatically controlling a train, train carriedequipment comprising brake-applying means, a combined forestalling andresetting device, said device permitting, by identical manual operation,prevention of an automatic application of the brakes provided nodeceleration of the train exceeding a certain rate has occurred,

After reand the release'of an automatic application provided thedeceleration of the train has attained a predetermined rate.

v 4. In an automatic train control system comprising a normally activerelay de-energized when a receiver on the locomotive reg.- istersinductively to form a magnetic couple with a traiiic controlled element,a brake initiating circuit controlled thereby, and a restoring circuitfor said relay including a manually operated switch normally retractedfrom the operating position and control ling normally open contacts inseries with inertia controlled contacts.

5. In an automatic train control system comprising a normally activerelay deenergized when a receiver on the locomotive registersinductively to form a magnetic couple with a trafiic controlled element,a brake initiating circuit controlled thereby, and a restoring circuitfor said relay including a manually operated switch normally retractedfrom the operating position and controlling normally open contacts inseries with inertia controlled contacts paralleled by speed controlledcontacts.

6. In an automatic train control system comprising a normally activerelay de-energized when a receiver on the locomotive registersinductively to form a magnetic couple with a traffic controlled element,a brake initiating circuit controlled thereby, a restoring circuit forsaid relay including a manually operated switch normally retracted fromthe operating position and controlling normally open contacts in serieswith inertia controlled contacts and means for opening the brakeinitiating circuit when-the restoring circuit is closed.

7. In a automatic train control system comprising a normally activerelay de-energized when a receiver on the locomotive registersinductively to form a magnetic couple with a traflic controlled element,a brake initiating circuit controlled thereby, a restoring circuit forsaid relay including a manually operated switch normally retracted fromthe operating position and controlling normally open contacts in serieswith inertia controlled contacts paralleled by speed controlledcontacts, and means for opening the brake initiating circuit when therestoring circuitis closed.

8. In an automatic train control system comprising a normally activerelay de-energized when a receiver on the locomotive registersinductively to form a magnetic couple with a traiiic controlled element,a brake initiating circuit controlled thereby, and a restoring circuitfor said relay including a manually operated switch normally retractedfrom the operating position and controlling normally open contacts inseries with inertia controlled contacts, said initiating circuitcomprising contacts bridged by said switch when in normal position.

9. In an automatic train control system comprising a normally activerelay de-energized when a receiver on the locomotive registersinductively to form a magnetic couple with a trafiic controlled element,a brake initiating circuit controlled thereby, and a restoring circuitfor said relay including a manually operated switch normally retractedfrom the operating position and controlling normally open contacts inseries with inertia controlled contacts paralleled by speed controlledcontacts, said initiating circuit comprising contacts bridged by saidswitch when in normal position.

New York, N. Y., July 3d, 1929.

FRANK J. SPRAGUE.

